SOMERVILLE — A woman leaned out a third-floor window and screamed for help Sunday night as flames and black smoke intensified on the floor below her.
“Help me!” she shouted. “Can’t breathe!”
That’s when Cecilio Rojo and his 16-year-old son, Jeffrey, rushed to her rescue, pulling a mattress out of their nearby apartment and placing it under the windows where she and her daughter were frantically trying to escape the blaze.
Their quick thinking worked.
“The two ladies jumped,” Rojo, 41, said Monday in his apartment building, which is managed by the city’s housing authority. ”The first one, the daughter, she didn’t break anything. She was fine. She just landed the mattress and we got her out of there."
At that moment, he stepped away to look for a ladder and considered grabbing a second mattress from his apartment, but ended up returning just as the second woman jumped out the window, he said.
“When we come back, that lady jumped, too,” he said. Unfortunately, one only of her feet landed on the mattress, and Rojo said he had been told she broke her leg.
“It was crazy. It was scary. All the screaming and that,” he said. “I didn’t think they were going to make it.”
The fire grew to two alarms and generated heavy flames and smoke. It likely started due to an unattended candle, officials said.
“Our investigation overnight and into the morning identified the area of origin as a second-floor bedroom,” said Fire Chief Charles Breen Jr. “Based on evidence at the scene, witness interviews, and other evidence, we believe it started with an unattended candle.”
The fire was reported around 11:05 p.m. and a central alarm system connected directly to the fire department functioned properly, officials said. All other fire safety systems operated as required.
Breen said the blaze was limited to one unit on the second floor. The person in that unit was rescued by firefighters and taken to a hospital with injuries that were not considered life-threatening. The person is expected to be released sometime Monday.
In addition to the two women Rojo helped rescue, one child was rescued via a ground ladder, and three adults were rescued using an aerial ladder placed against the structure, officials said. Four residents were taken to local hospitals.
Four firefighters also sustained minor injuries, officials said.
The housing authority has been updating its plans for emergencies at its properties but has not yet completed the process, officials said.
At least nine apartments are no longer habitable, officials said.
The housing authority’s executive director, Diane L. Cohen,said in a statement that sprinkler systems were not required by the state’s fire code because of the age of the building.
Officials are working to find short-term and long-term housing for 18 people displaced by the fire, Cohen said. One resident said he was given a room at the Fairfield Marriott in Cambridge.
“We are committed to supporting those impacted by this incident in every way possible, and we are grateful to the first responders whose quick actions saved lives last night,” Cohen said.
In the master bedroom of Rojo’s first-floor apartment, a wooden bedframe is now without its mattress.
When Rojo’s family finally got to sleep around 6 a.m. on Sunday, Rojo slept on the couch.
But it was an easy sacrifice to make.
“You don’t think .. when you see these kinds of emergencies,” he said. “All you want to do is help somehow ... that’s the most important thing.”
John R. Ellement of the Globe Staff contributed to this report.
Truman Dickerson can be reached at truman.dickerson@globe.com.